With rookie quarterbacks Andrew Luck, Robert Griffin III and Russell Wilson leading their respective NFL teams to the playoffs and fellow first-year standout Luke Kuechly leading the league in tackles, it is more obvious than ever the immediate impact rookies can make in today's NFL.

The first (and best) opportunity NFL teams, media and the public will have to see the best of the 2013 draft class kicks off in less than two weeks with the annual scouting combine in Indianapolis.

Inside the walls of Lucas Oil Stadium the 333 college prospects ranked highest by league scouts will be poked, prodded, tested and questioned, helping teams set their draft boards in preparation for the April draft.

Any conversation about the 2013 offensive line must begin with Texas A&M junior left tackle Luke Joeckel, NFLDraftScout.com's top overall prospect.

He, along with Senior Bowl standouts Eric Fisher and Lane Johnson, possesses the size and athleticism to contribute immediately at the premium "blindside" position.

Perhaps most exciting about the 2013 class of tackles, however, is the depth, as there are several exciting developmental prospects likely to still be on the board in the middle rounds.

The guard class is similarly strong, with both Chance Warmack and Jonathan Cooper likely to hear their names called in the first round.

The center class, on the other hand, isn't as talented or deep as it has been in recent years.
Most to gain in Indianapolis

Logic says that the players who put forth the most impressive workout results have the most in gain at the combine each year. That isn't necessarily the case. In most cases, the elite athletes are already well known by scouts. The players who actually boost their grades during the athletic drills at the combine are those who show better-than-expected athleticism or help their cause through interviews.

Take Wisconsin's Rick Wagner and Oregon's Kyle Long as examples.

Wagner has long been a standout for the Badgers but is not the physically dominant run-blocker Wisconsin has consistently sent into the NFL. He is, however, light on his feet, especially given the fact he sports a 6-foot-6-inch, 310-pound frame. A solid showing at the combine could help him further differentiate himself from the stereotyping some scouts or NFL coaches might do if seeing him for the first time.

Long, the son of Hall of Fame defensive end Howie and brother of St. Louis Rams defensive end Chris, is well known for his athleticism. He was drafted by the Chicago White Sox as a pitcher and emerged as a starter late last year for the Ducks despite having played college football for only two years.

Make no mistake, however: Long's time in Eugene was short. He started just four games in 2012, with each of them coming at left guard, not outside at tackle as his 6-6, 304-pound frame would seem to suggest he'd fit best. Furthermore, scouts will want to interview him. Long was arrested and charged with DUI in 2009, and after only three seasons of college football, he'll need to prove on the white board that he understands the complexities of today's blocking schemes.

Medical watch

For all of the talk about 40-yard dash, vertical jumps and bench press totals that will dominate coverage of the combine, the single-most critical element is always the medical testing taking place in Indianapolis. Players have the option of passing on workouts at the combine, but every one of the 333 players invited will be subjected to a battery of medical evaluations that range from blood tests to X-rays to psychological testing.

Receiving a "red flag" on a medical test can destroy a player's draft stock. Former Washington running back Chris Polk entered the combine a year ago widely viewed as a top prospect, but after medical tests showed extensive damage done to his shoulders and knees, he fell out of the draft entirely. To his credit, Polk made the Philadelphia Eagles roster as an undrafted free agent.

The brutality of the trenches make the medical grades on offensive and defensive linemen all the more important to their final draft stock. LSU's Chris Faulk (ACL), North Carolina's Brennan Williams (torn labrum) and California's Matt Summers-Gavin (recurring right knee injuries) are three players whose play could warrant consideration in the first three rounds, but only if teams are satisfied with their health.

Tale of the tape

With scouts having seen most of the top prospects "on the hoof" over the fall and getting a second look at them on the "catwalk" prior to senior all-star games, the official measuring of heights, weight, hand and arms conducted during the Combine is only occasionally newsworthy ... except when it comes to underclassmen, whom scouts often haven't seen up close yet.

As such Colorado's David Bakhtiari and LSU's Faulk have a lot riding on how they measure up in Indianapolis.

Bahtktiari was listed by Colorado at 6-4, 295 pounds. By today's standards, that's light for an NFL offensive lineman, and some scouts wonder if he has the arm length and balance to handle remaining outside. If moved inside, Bahktiari might have to add mass, especially in his lower body to be able to anchor against today's massive defensive tackles.

Faulk, listed at 6-6, 323, on the other hand, has shown remarkably light feet while protecting the edge against SEC speed. He has carried more weight across his middle, however, than one normally sees in today's left tackles, so his overall fitness will be evaluated by scouts.

Next question

Just like any interview you or may have gone through, the players invited to the combine are there to try and a job. They have to impress their potential employers with intelligence and dedication.

Each NFL team is allowed 60 formal player interviews. Each interview can last up to 15 minutes. The topics of conversation can fluctuate wildly from team to team and from player to player.

One under-the-radar player who could have full "dance card" is West Texas A&M offensive tackle Manase Foketi.

Foketi signed with Kansas State as a highly regarded JUCO prospect and performed well at this position in 2010. He tore his Achilles tendon two games into the 2011 season and was given a redshirt. Rather than return to the team in 2012, Foketi decided he wanted to transfer for his final season of eligibility.

For reasons that teams will want to explore, the highy respected Bill Snyder and his staff would not allow Foketi to transfer to another FBS program. Foketi wound up transferring to the Buffaloes where the talented 6-5, 333-pound left tackle, not surprisingly dominated. He was named one of three finalists for the Gene Washington Division II Offensive Lineman of the Year Award. His play caught the attention of the East-West Shrine Game talent scouts. After agreeing to play (and being measured in preparation to practice), he apparently sufferered an undisclosed injury early in the week and left. As such, teams will have plenty of questions for him.

Workout warriors

While the medicals, weigh-ins, and interviews all play more critical roles in a player's overall grade than his performance during athletic testing at the combine, there is no doubt that the extraordinary athleticism demonstrated during drills can leave scouts (and the media) buzzing. This hype has helped push players up draft boards in the past and it will continue to do so in 2013.

Two offensive linemen who are expect to dazzle in workouts this year are Arkansas Pine-Bluff's Terron Armstead and Florida State's Menelik Watson.

The 6-5, 306 pound Armstead is already rising up draft boards after proving himself to be the most talented blocker at the East-West Shrine Game and performing well as a late injury-replacement at the Senior Bowl. He could have signed with more a more prominent program out of high school but signed with Arkansas Pine-Bluff because it was the only school that would allow him to participate in both football and track, as he was a state champion shot-putter.

Watson, a junior, is an even more fascinating story. A native of Manchester, England, the 6-5, 320 pounder originally planned to use basketball as an avenue to athletic stardom and tried his hands at boxing before ultimately switching to football. After just one year at Saddlebrook Community College in California, FBS programs across the country had heard of his unbelievable athleticism and were racing to sign him. He signed with the Seminoles over Oklahoma, Oregon and Rutgers, among others. The FSU coaches pleaded with him to return for his senior season, but Watson left after just one season in Tallahassee. He certainly is raw, but don't be surprised at all when he proves to be one of the combine's biggest stars.